Characterization of an Improved Extraction Chromatographic Material for the Separation and Preconcentration of Strontium from Acidic Media

Abstract:

The determination of radiostrontium in biological and environmental samples generally requires its preliminary separation and preconcentration, both to remove radionuclides that may interfere with subsequent β-counting and to free it from the large quantities of inactive substances present (e.g., calcium). Extraction chromatography employing an inert support impregnated with a solution of a crown ether in an oxygenated, aliphatic solvent (e.g., 1-octanol) has previously been demonstrated to provide a simple and effective method for the isolation of strontium from a variety of samples for subsequent determination. In this work, it is shown that a chromatographic resin capable of retaining strontium efficiently and selectively from acidic media can be prepared simply by dispersing a crown ether alone on an appropriate support. This “solventless” resin is demonstrated to offer several advantages over its conventional analog, in particular, good physical stability, higher capacity, and improved metal ion retention. In addition, extended X-ray absorption tine structure measurements are shown to provide insight into the coordination environment of metal ions sorbed by the resin.